Mammography apparatus

ABSTRACT

A mammography apparatus includes a detector that detects X-rays transmitted through a breast, and an optically transparent or semitransparent pressing panel for pressing the breast. The apparatus further includes a near infrared ray source that provided between the X-ray source and the pressing panel and arranged in a two-dimensional shape in alignment with the pressing panel, and that is movable between a first position in close contact with the pressing panel and a second position outside an X-ray image capture region. Near infrared image capture is carried out using the near infrared ray source by causing the near infrared ray source to be in the first position, and the near infrared ray source is caused to retract to the second position when carrying out X-ray image capture using the X-ray source.

RELATED APPLICATIONS

This is a continuation of Ser. No. 13/114,144, filed May 24, 2011, whichis a continuation of Ser. No. 12/576,368, filed Oct. 9, 2009. Thisapplication claims benefit of both of those applications under 35 U.S.C.§120, and claims benefit under 35 U.S.C. §119 of Japanese PatentApplication No. 2008-285707, filed Nov. 6, 2008. The entire contents ofeach of the mentioned prior applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to mammography apparatuses that obtainX-ray images of mammary specimens using X-ray imaging.

2. Description of the Related Art

Mammography apparatuses that obtain X-ray images of mammary specimensusing X-ray imaging include mammography apparatuses that usesemiconductor two-dimensional image detectors. These are configuredmainly with an X-ray source, a pressing panel for pressing the breast, atwo-dimensional X-ray image detector that holds the breast and images anintensity distribution of transmitted X-rays. Two-dimensional imagedetectors are produced by combining phosphor, which converts the X-raysto visible fluorescence, and a semiconductor two-dimensional imagedetector (see Japanese Patent Laid-Open No. 08-238233 for example).

Some mammography apparatuses use a grid to suppress scattered X-rays(see Japanese Patent Laid-Open No. 2005-013344 for example).

Furthermore, some apparatuses perform imaging with the X-ray image andan ultrasonic image of the breast under a same pressing condition. Forexample, infrared rays are used in a sensor that detects a position ofan ultrasonic probe in regard to these apparatuses. The breast ispressed in a same manner for obtaining the X-ray image and for obtainingthe ultrasonic image, and therefore as a result it is possible tocombine the ultrasonic image and the X-ray image (see Japanese PatentLaid-Open No. 2003-260046 for example).

Furthermore, techniques have been proposed (see Japanese PatentLaid-Open No. 09-505407 for example) in which a breast image is capturedby irradiating near infrared rays onto a breast through a breastcompressing panel and collecting transmitted light using optic fibers.

Further still, techniques have been proposed (for example, see SergioFantini et al, “Using Near-Infrared Light To Detect Breast Cancer,”Optics & Photonics News, November, 2003) in which a near infrared imageof a breast is obtained by causing a plurality of amplitude-modulatednear infrared rays to be incident on a single optic fiber thentransmitting this onto the breast and performing homodyne detection onthe transmitted near infrared rays.

In breast cancer diagnosis using mammography apparatuses,reproducibility of positioning between the imaging apparatus and thebreast is sometimes required for cytology and histology in a case wherea positive result is doubted or during postoperative observations overtime.

However, conventional mammography apparatuses do not have a positioningfunction.

On the other hand, although there are cases where near infrared imagesare effective in discovering tumorous cancer, which is a weak point forX-ray images, there is a problem in that it has not been possible toachieve a correspondence between the positions of the morbid portiondiscovered in the near infrared image and the X-ray image.

SUMMARY OF THE INVENTION

In light of the foregoing problems, the present invention provides amammography apparatus capable of reproducing breast positioning duringbreast X-ray imaging for example.

In one aspect of the present invention, a mammography apparatus forcapturing an X-ray image of a breast, comprises an X-ray source, adetector having a placement surface on which a breast is placed on aside opposing the X-ray source and that detects X-rays transmittedthrough the breast, wherein the detector is capable of detecting nearinfrared rays as well as being capable of detecting X-rays, an opticallytransparent or semitransparent pressing panel for pressing the breastthat is placed on the placement surface against the placement surface, atwo-dimensional near infrared ray source that is provided between theX-ray source and the pressing panel and arranged in a two-dimensionalshape in alignment with the pressing panel, and that is movable betweena first position in close contact with the pressing panel and a secondposition outside an X-ray image capture region, and a controller thatcarries out near infrared image capture using the two-dimensional nearinfrared ray source by causing the two-dimensional near infrared raysource to be in the first position, and causes the two-dimensional nearinfrared ray source to retract to the second position when carrying outX-ray image capture using the X-ray source.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D are outlines of a mammography apparatus according to thepresent embodiment.

FIG. 2 is a diagram showing operation of a pressing panel when capturingan image for breast positioning.

FIGS. 3A and 3B are diagrams showing a structure of a two-dimensionaldetector.

FIGS. 4A and 4B are diagrams showing advancement and retraction of alaser diode matrix.

FIGS. 5A and 5B are diagrams showing a structure of a laser diodematrix.

FIG. 6 is a diagram showing one pixel of a semiconductor sensor.

FIG. 7 is a diagram in which pixels of the semiconductor sensor arearranged two-dimensionally.

FIG. 8 is a flowchart of a control process relating to X-ray breastimaging according to the present embodiment.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the presentinvention will be described in detail below with reference to thedrawings.

FIGS. 1A to 1D show outlines of a mammography apparatus according to thepresent embodiment.

FIG. 1B is a front view showing a state of the apparatus when capturinga CC (cranio-caudad) image of a breast 6, and is a diagram in which themammography apparatus is viewed from an examinee (patient). Arranged inorder from above are an X-ray source 1, a laser diode matrix 2, apressing panel 3, an X-ray grid 4, and a two-dimensional detector 5.FIG. 1A is a front view showing a state of the apparatus when capturingan MLO (medio-lateral oblique) image of the breast 6. A difference fromthe front view (when CC) of FIG. 1B is that a capture section is tilted.

Here, the two-dimensional detector 5 is a detector having a placementsurface on which the breast 6 is placed on a side opposing the X-raysource 1.

Description is given of a state of the apparatus at a time of obtainingan infrared image and a time of breast positioning shown in FIG. 1C. Inthis state, no X-rays are exposed from the X-ray source 1. The breast 6of an examinee placed on the placement surface of the two-dimensionaldetector 5 is pressed by the pressing panel 3 against the placementsurface. The laser diode matrix 2, which is a two-dimensional nearinfrared ray source arranged in a two-dimensional shape in alignmentwith the pressing panel 3, is provided above the pressing panel 3. Thelaser diode matrix 2 is configured to be movable between a firstposition in close contact with the pressing panel 3 and a secondposition outside an X-ray image capture region. A plurality of nearinfrared laser diodes are arranged in a matrix shape in the laser diodematrix 2. The pressing panel 3 is an optically transparent orsemitransparent material through which near infrared rays aretransmitted, and is a material through which X-rays are readilytransmitted, for example an acrylic or the like is appropriate.

The near infrared rays emitted from the near infrared laser diodes aretransmitted through the pressing panel 3 and proceed while undergoingattenuation and diffusion through the breast 6 to reach thetwo-dimensional detector 5. The X-ray grid 4 that does not transmit nearinfrared rays is retracted. The two-dimensional detector 5 includes atwo-dimensional semiconductor detector having sensitivity to visiblelight and near infrared ray. That is, the two-dimensional detector iscapable of detecting visible light and near infrared rays as well asbeing capable of detecting X-rays. A near infrared image of the breast 6is calculated based on an intensity distribution of light incident onthe two-dimensional detector 5. Here, the time of breast positioning isused because by displaying a near infrared image of the breast 6 in realtime, an imaging technician becomes capable of reproducing a positioningstate of the breast 6 based on vascular arrangement in the breast 6.

Description is given regarding differences between imaging for breastpositioning and imaging of near infrared images. All of these images areformed using near infrared rays. However, at a time of imaging forbreast positioning, increased speeds in image forming times are requiredfor the imaging technician to respond to changes in the breast settings.In this regard, time is required in imaging a breast spectroscopic imageusing near infrared laser diodes of multiple wavelengths in the laserdiode matrix 2.

Shortening the imaging times becomes possible by decimating rather thanlighting all the laser diodes incorporated in the laser diode matrix 2,thereby sacrificing image resolution to give priority to real timecapabilities.

Compared to imaging for breast positioning, imaging of near infraredimages is high resolution, and although it is spectroscopic, the imagingtimes become longer.

Next, description is given of a state of the apparatus shown in FIG. 1Dwhen capturing an X-ray image.

The X-ray image is captured after breast positioning is completed. Whenimaging for breast positioning and imaging of the near infrared imageare completed, the laser diode matrix 2 retracts from the X-ray imagecapture region.

On the other hand, the retracted X-ray grid 4, which is retracted at atime of imaging for breast positioning, is inserted above thetwo-dimensional detector 5. When the retraction of the laser diodematrix 2 and the insertion of the X-ray grid 4 are confirmed, X-rays areexposed.

In this regard, there is a correlation between a transmission amount ofnear infrared rays when imaging a near infrared image and a transmissionamount of X-rays. A positive correlation is known between breastthickness and mammary gland density and the amount of light that reachesthe two-dimensional detector 5. Using this relationship, it is possibleto determine an X-ray target, an X-ray filter, an X-ray tube current,and an imaging time when imaging an X-ray image. For example, in a casewhere the amount of light that reaches the detector is a specific valueor less, it is conceivable to use rhodium as the X-ray target ratherthan molybdenum. Furthermore, it is possible to increase the X-ray tubecurrent inversely proportional to the amount of light that reaches thedetector. In a case where the X-ray tube current cannot be increased dueto a limitation of the X-ray source, the imaging time is increased.

FIG. 2 indicates an operation of the pressing panel 3 when capturing animage for breast positioning and a timing of lighting the near infraredlaser diodes. Although the position setting of the breast and thecommencement of breast pressing are determined by the imaging technicianwhile confirming the safety of the patient, the lighting of the laserdiodes commences automatically when a predetermined pressing force orgreater is applied to the pressing panel 3. When capture of thepositioning image is completed, the lighting of the laser diodes stops.

Positioning images are displayed on a display device not shown in thediagrams. When the imaging technician judges that the positioning isappropriate, a transition is made to capturing a high resolution nearinfrared image. Images for judging the suitability of positioning caninclude displaying a difference image between a past image and a currentimage as well as being displayed in parallel to a previously capturedimage. A relative relationship between the images is important informing a difference image. A correlation coefficient of the two imagescan be calculated as an indicator of the relative relationship. Byperforming image shifting based on the correlation coefficient in adirection in which the correlation coefficient becomes larger, betterpositioning can be achieved.

FIGS. 3A and 3B are diagrams showing a structure of the two-dimensionaldetector 5.

When capturing an image for positioning and a near infrared image shownin FIG. 3A, the laser diode matrix 2 is arranged in close contact to anupper surface of the pressing panel 3. Hereinafter, an image forpositioning and a near infrared image are both indicated when referringto a near infrared image.

Near infrared rays that have been transmitted through the pressing panel3 and the breast 6 are incident on the two-dimensional detector 5. Thetwo-dimensional detector 5 has a protective panel 8, a wavelength filter9, an X-ray phosphor 10, a semiconductor sensor 11, and a sensorelevation mechanism 12.

The protective panel 8 protects the semiconductor sensor 11 duringbreast pressing. The protective panel 8 is a material having littleX-ray attenuation and through which near infrared rays are transmitted.For example, acrylic or reinforced glass can be used.

The wavelength filter 9 is a filter that transmits near infrared rays orrays of longer wavelengths than near infrared rays, and is a filmthrough which visible light and far infrared rays are not transmitted.

The X-ray phosphor 10 transmits near infrared rays, and generatesfluorescence with respect to incident X-rays. A CsI columnar crystal isappropriate as an example of the X-ray phosphor 10. Because it iscolumnar, diffusion of X-ray fluorescence and near infrared rays can bereduced.

A CMOS sensor for example can be used as the semiconductor sensor 11.Amorphous silicon sensors widely used in X-ray images cannot be usedsince they have no sensitivity to near infrared.

The sensor elevation mechanism 12 is a mechanism for adjusting thedistance between the lower surface of the protective panel 8 and theupper surface of the wavelength filter 9. By bringing the lower surfaceof the protective panel 8 and the upper surface of the wavelength filter9 close together, it is possible to reduce resolution deterioration innear infrared images.

When performing breast imaging, high resolution is demanded for theX-ray image, and for example a pixel pitch of 100 μm is necessary.

However, since X-ray images are still images, high speed image readoutis not required. On the other hand, a required resolution of nearinfrared images is approximately 1 to 3 mm High speed image readout isnecessary for near infrared images.

Accordingly, with a pixel size of 100 μm, the structure of thesemiconductor sensor 11 is a structure capable of reading clusters of8×8 images, 16×16 images, or 32×32 pixels.

Furthermore, although X-ray images are formed at one time over theentire surface of the semiconductor sensor 11, near infrared images arelimited to a region of approximately 10 mm×10 mm with respect to asingle laser diode. Thus, when capturing a near infrared image, it isnecessary to perform partial (local) high speed reading at the same timeas cluster reading.

Furthermore, the semiconductor sensor 11 changes the image pickup regionin response to the resolution that is set when capturing a near infraredimage. A relative positional relationship between the laser diode matrix2 and the two-dimensional detector 5 can be known in advance bycalibration.

Next, description is given of a structure of FIG. 3B when capturing anX-ray image.

When capturing an X-ray image, the laser diode matrix 2 retracts and theX-ray grid 4 is inserted between the protective panel 8 and thewavelength filter 9. The X-ray grid 4 has an effect of reducing X-rayscattering. A gap between the protective panel 8 and the wavelengthfilter 9 is formed by downwardly shifting as a group the wavelengthfilter 9, the X-ray phosphor 10, and the semiconductor sensor 11 usingthe sensor elevation mechanism 12.

On the other hand, it is also possible to bring the wavelength filter 9in close contact with the lower surface of the protective panel 8 andinsert the X-ray grid 4 in a gap between the wavelength filter 9 and theX-ray phosphor 10. However, from a perspective of shielding thesemiconductor sensor 11, the foregoing method of inserting the X-raygrid 4 between the protective panel 8 and the wavelength filter 9 isbeneficial.

In this regard, a commonly known X-ray grid 4 is not a structure thattransmits near infrared rays. The X-ray grid 4 is a structure in whichwood or fiber or the like is sandwiched between lead foil.

However, it is possible to sandwich between the lead foil a fiber thattransmits near infrared rays.

When an X-ray grid 4 such as this capable of transmitting near infraredrays is used, the operations of inserting and retracting the grid becomeunnecessary, and optical shielding of the two-dimensional detector 5 iseasy.

FIGS. 4A and 4B show advancement and retraction of the laser diodematrix 2.

The pressing panel 3 is secured on a pressing panel support frame 13.The pressing panel support frame 13 is installed so as to be capable ofvertical movement on a support upper frame 7 of the imaging apparatus.

As shown in FIG. 4A, when capturing a near infrared image, the laserdiode matrix 2 slides on the pressing panel support frame 13 andadvances over the pressing panel 3. After advancement, the laser diodematrix 2 is brought in close contact with the pressing panel 3 using asuction or a pressure clamping mechanism (not shown in diagrams).

As shown in FIG. 4B, when capturing an X-ray image, the laser diodematrix 2 slides on the pressing panel support frame 13 to retract afterthe close contact is released.

FIGS. 5A and 5B show a structure of the laser diode matrix 2. The laserdiode matrix 2 is a two-layer structure.

First, description is given of an example in FIG. 5A.

In an upper portion, laser diodes 14 are arranged two-dimensionally, andin a lower portion, fibers are arranged two-dimensionally. The laserdiodes 14 and the fibers are made to correspond one to one, and adhered,pressed, or bound together.

In the example of FIG. 5B, four near infrared laser diodes 16 ofdifferent frequencies correspond to a single fiber as a group. By usingnear infrared rays of multiple frequencies, spectroscopy of the breast 6can be achieved.

In a case of achieving spectroscopy, four near infrared laser diodes 16having different frequencies are made to correspond to a single fiber inthe working example shown in FIG. 5B, but it is also possible to make alaser diode of each frequency corresponds to a single fiber.

FIG. 6 shows one pixel of the semiconductor sensor 11. Light incident ona photo diode 17 is converted to an electrical signal, a transfer switchsignal 18 becomes ON, and then the signal is output via a preamplifierby undergoing line selection.

FIG. 7 is a diagram in which pixels of FIG. 6 are arrangedtwo-dimensionally. Output of each pixel in an 8×8 array is selected by avertical shift register 24 and a horizontal shift register 25. Output ofa selected pixel is outputted via an amplifier 26. To capture an entirebreast image, a two-dimensional detector 5 is necessary having aneffective area of at least 20 cm×24 cm. This size can be achieved with asingle semiconductor sensor 11 using amorphous silicon, but for acrystal semiconductor such as CMOS, this size is currently impossible.On the other hand, when capturing a near infrared image, high speedlocal readouts are necessary. Accordingly, in the present embodiment,sensors of approximately 256×256 pixels are arranged in a tile shape toachieve an overall size of approximately 20 cm×24 cm.

Description is given regarding a function of the amplifier 26 of FIG. 7.

When reading out an X-ray image, pixels are selected one by one by thevertical shift register 24 and the horizontal shift register 25. Aconstant multiple setting is performed for a gain change signal 27, andtherefore a signal of the selected signal is amplified by the constantmultiple and output. When reading out the near infrared image, pixels ofa range surrounded by the dashed line are selected and output at thesame time. In the case of FIG. 7, 4×4 pixels are selected at the sametime. An added signal of selected pixel signals is amplified by theamplifier 26. Gain change is performed using the gain change signal 27during amplification. A signal of a frequency approximating a frequencyof an intensity modulated signal of the laser diodes is used as the gainchange signal 27.

Spectroscopic imaging methods using near infrared rays are described indetail in the above-mentioned Sergio Fantini et al, “Using Near-InfraredLight To Detect Breast Cancer,” Optics & Photonics News, November, 2003.Here, simple description is given of a method in which near infraredrays of four wavelengths are used.

Laser diode lights of 690 nm, 750 nm, 788 nm, and 856 nm are used forthe four wavelengths. The light of the four wavelengths undergoesamplitude modulation at 70.45 MHz, 70.20 MHz, 69.80 MHz, and 69.5 MHzrespectively.

Amplitude modulated light is made incident on the breast 6 clusteredinto a single fiber as shown in the structure shown in FIG. 5B. Lightthat is transmitted through the breast 6 is incident on a single regionof cluster reading pixels 23 shown in FIG. 7. Incident signals areamplified by the amplifier 26, and a 70 MHz signal is used in the gainchange signal 27 when amplifying.

Signals of four wavelengths are separated from a gain change outputsignal 28 such that four near infrared images can be formed.

Spectroscopy is created by combining the four images using imageprocessing. This system is referred to as frequency domain opticalmammography, but the near infrared images used in the present inventionare not limited to this system, and configurations according to thepresent invention can be used in other systems also.

Description is given regarding a case where differences occur from thefrequency domain system disclosed in Sergio Fantini et al, “UsingNear-Infrared Light To Detect Breast Cancer,” Optics & Photonics News,November, 2003. When collecting near infrared rays, in the foregoingdescription, only a single location of cluster reading pixels 23 areread out with respect to emitted rays of the single laser diode (in thecase of FIG. 5B, four laser diodes forming a single group).

However, when consideration is given to a case where diffusioninformation of the near infrared rays also includes information, it isconceivable to read out multiple cluster reading pixels 23.

For example, when reading out four cluster reading pixels 23, reading isperformed serially (successively), and therefore phase differences occurin the gain change.

Accordingly, it is necessary to give consideration that there are phasedifferences between the four pixels when extracting beats using homodynedetection. Note however that the phase differences of the four clusterreading images are already known since these correspond to a read-infrequency of the semiconductor sensor.

Description is given regarding an image correction method. Inconventional two-dimensional detectors 5 specialized for X-ray images, athin aluminum sheet is used instead of the wavelength filter 9. In thiscase, there is no risk that visible light, near infrared rays, orinfrared rays will be incident. However, depending on characteristics ofthe wavelength filter 9, there is a risk that small amounts of visiblelight, near infrared rays, or infrared rays will be incident on thesemiconductor sensor 11 when near infrared rays are not being emittedfrom the laser diodes.

Furthermore, the structure is complicated compared to the conventionaltwo-dimensional detector 5 specialized for X-ray images, and thereforethere is also a risk that the above-mentioned light will be incident inminute amounts. These lights become offsets and reduce the contrast inimages.

Consequently, before capturing the near infrared image of FIG. 3A andcapturing the X-ray image, black images (dark images) are capturedrespectively and subtracted from the acquired images respectively.Furthermore, shading correction is possible by capturing a white imagewhen capturing the near infrared image and when capturing the X-rayimage respectively and dividing these by the acquired images. The whiteimage is an image in a case where the laser diodes or X-rays are emittedwhile there is no subject.

Finally, description is given using a flowchart of FIG. 8 of a controlprocess relating to X-ray breast imaging according to the presentembodiment.

Acquisition of a correction image is carried out at S0 before imaging ofa patient. Correction images are acquired immediately prior to patientimaging giving consideration to temperature drift of the two-dimensionaldetector 5.

Imaging of the patient commences at S1. At S2, the technician performsinitial setting of the breast 6 of the patient on an imaging platform.At S3, the laser diode matrix 2 advances to a first position in closecontact with the pressing panel 3, and the X-ray grid 4 retracts. At S4,the pressing panel 3 is lowered by operation of the technician, and whenpressure is detected at S5, light is emitted from the laser diodes at S6and imaging commences.

When exposure from each laser diode and transmitted light detection iscompleted at S7, a comparison is carried out with a past near infraredimage at S8. The comparison may also involve displaying a differenceimage.

At S9, a confirmation of position reproducibility is carried out. Ifreproducibility is confirmed, a high precision near infrared image iscaptured at S10.

At S11, the laser diode matrix 2 retracts to a second position outsidean X-ray image capture region, and the X-ray grid 4 is inserted. At S12,X-ray exposure is carried out and at S13, X-ray image acquisition iscarried out. The near infrared image and the X-ray image are capturedunder identical conditions, and therefore at S14 it is possible to carryout image processing overlaying the images without needing to performgeometrical conversions. The X-ray image displayed in black and whiteand the near infrared image displayed in color can be overlaid. At S15,imaging is completed.

With the present invention, reproduction of breast settings (capturemethod) is possible in X-ray breast imaging.

This enables near infrared images and X-ray images to be captured underidentical conditions.

Furthermore, by displaying an overlay of the near infrared image and theX-ray image, an overlay of calcified cancer and tumorous cancer can becarried out with excellent accuracy.

Furthermore, it becomes possible to estimate an appropriate imaging dosewhen transitioning from a near infrared image to X-ray imaging.

Further still, images having excellent contrast can be achieved bycapturing in advance images for correction of the near infrared imageand the X-ray image respectively from the same sensor.

Other Embodiments

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiment(s), and by a method, the steps ofwhich are performed by a computer of a system or apparatus by, forexample, reading out and executing a program recorded on a memory deviceto perform the functions of the above-described embodiment(s). For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (e.g., computer-readable medium).

An embodiment of the present invention can provide a mammographyapparatus for capturing an X-ray image of a breast, comprising: an X-raysource; a detector having a placement surface on which a breast isplaced on a side opposing the X-ray source and that detects X-raystransmitted through the breast, wherein the detector is capable ofdetecting near infrared rays as well as being capable of detectingX-rays; an optically transparent or semitransparent pressing panel forpressing the breast that is placed on the placement surface against theplacement surface; a two-dimensional near infrared ray source that isprovided between the X-ray source and the pressing panel and arranged ina two-dimensional shape in alignment with the pressing panel, and thatis movable between a first position in close contact with the pressingpanel and a second position outside an X-ray image capture region, and acontroller that carries out near infrared image capture using thetwo-dimensional near infrared ray source by causing the two-dimensionalnear infrared ray source to be in the first position, and causes thetwo-dimensional near infrared ray source to retract to the secondposition when carrying out X-ray image capture using the X-ray source.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

1. A detection apparatus comprising: a detection unit configured todetect near infrared rays and X-rays, said detection unit having alight-receiving surface to receive the near infrared rays and X-rays; agrid provided on a side of a light-receiving surface of the detectionunit; and a control unit configured to control, when the near infraredrays are irradiated, said grid to evacuate to an area which does notintercept the near infrared rays irradiated to said light-receivingsurface of said detection unit.
 2. The apparatus according to claim 1,further comprising a near infrared ray source configured to emit thenear infrared rays, wherein, when the X-rays are irradiated, saidcontrol unit controls said near infrared ray source to evacuate to anarea which does not intercept the X-rays irradiated to saidlight-receiving surface of said detection unit.
 3. The apparatusaccording to claim 1, wherein when the X-rays are irradiated, saidcontrol unit controls said grid to move said grid into an area where theX-rays are irradiated.
 4. The apparatus according to claim 1, furthercomprising: a wavelength filter configured to transmit at least nearinfrared rays and not to transmit visible light; a phosphor configuredto transmit near infrared rays transmitted through said wavelengthfilter, and to generate fluorescence with respect to incident X-rays;and a semiconductor sensor configured to sense near infrared raystransmitted through said phosphor and to sense the fluorescence.
 5. Theapparatus according to claim 4, wherein said phosphor comprises acolumnar crystal.
 6. The apparatus according to claim 5, wherein saidcolumnar crystal comprises CsI.
 7. The apparatus according to claim 4,wherein said semiconductor sensor comprises a CMOS sensor.
 8. Theapparatus according to claim 4, further comprising a protection plateconfigured to protect said light-receiving surface, wherein saidprotection plate comprises a placement surface on which an object isplaced.
 9. The apparatus according to claim 8, wherein said control unitcontrols said grid to insert said grid into and remove said grid from aposition between said protection plate and said wavelength filter. 10.The apparatus according to claim 2, further comprising an X-ray sourceconfigured to emit the X-rays, wherein, when capturing near infraredimage, said control unit controls said near infrared ray source to movesaid near infrared ray source into an area where the near infrared raysare irradiated, and when capturing X-ray image, said control unitcontrols said near infrared ray source to evacuate from the area wherethe X-rays are irradiated.
 11. A detection apparatus for capturing animage using near infrared rays having multiple wavelengths emitted froma near infrared ray source and X-rays emitted from an X-ray sourcecomprising: a detection unit configured to detect near infrared rayshaving multiple wavelengths and X-rays; and a processing unit configuredto process a signal output from said detection unit as an X-ray imagewhen X-rays are irradiated, and process the signal as a near infraredray image corresponding to each of the multiple wavelengths when X-raysare not irradiated and near infrared rays having the multiplewavelengths are irradiated.
 12. The apparatus according to claim 11,wherein the near infrared rays of each of the multiple wavelengths aresubjected to different amplitude-modulation with respect to apredetermined frequency, the apparatus further comprising an amplifierconfigured to modulate a gain using a gain change signal of thepredetermined frequency and amplify output signal of said detectionunit, and wherein said processing unit separates the gain change signaloutput from said amplifier to obtain images each of which corresponds toa respective one of the wave lengths.
 13. The apparatus according toclaim 12, wherein said detection unit comprises a plurality of pixelsarranged in a two-dimensional shape, and wherein said amplifieramplifies output signals for each of said plurality of pixels.
 14. Theapparatus according to claim 11, further comprising a near infrared raysource configured to emit near infrared rays having the multiplewavelengths.
 15. The apparatus according to claim 14, wherein said nearinfrared ray source comprises near infrared laser diodes arranged in atwo-dimensional shape.
 16. An X-ray mammography apparatus comprising: anear infrared ray source configured to emit near infrared rays; an X-raysource configured to irradiate X-rays; a detection unit configured todetect the near infrared rays and the X-rays, said detection unit havinga light-receiving surface; a grid provided on a side of saidlight-receiving surface of said detection unit; a control unitconfigured to control, when the near infrared rays are irradiated, saidgrid to evacuate to an area which does not intercept the near infraredrays irradiated to said light-receiving surface of said detection unit.17. An X-ray mammography apparatus comprising: a near infrared raysource configured to emit near infrared rays; an X-ray source configuredto irradiate X-rays; a detection unit configured to detect near infraredrays having multiple wavelengths and X-rays; and a processing unitconfigured to process a signal output from said detection unit as anX-ray image when X-rays are irradiated, and process the signal as a nearinfrared ray image corresponding to each of the multiple wavelengthswhen X-rays are not irradiated and near infrared rays having themultiple wavelengths are irradiated.